Integrated Assemblies Having Thicker Semiconductor Material Along One Region of a Conductive Structure than Along Another Region, and Methods of Forming Integrated Assemblies

ABSTRACT

Some embodiments include an integrated assembly having a conductive structure which includes a semiconductor material over a metal-containing material. A stack of alternating conductive levels and insulative levels is over the conductive structure. A partition extends through the stack. The partition has wall regions, and has corner regions where two or more wall regions meet. The conductive structure includes a first portion which extends directly under the corner regions, and includes a second portion which is directly under the wall regions and is not directly under the corner regions. The first portion has a first thickness of the semiconductor material and the second portion has a second thickness of the semiconductor material. The first thickness is greater than the second thickness. Some embodiments include methods of forming integrated assemblies.

TECHNICAL FIELD

Integrated assemblies (e.g., three-dimensional NAND), and methods offorming integrated assemblies.

BACKGROUND

Memory provides data storage for electronic systems. Flash memory is onetype of memory, and has numerous uses in modem computers and devices.For instance, modem personal computers may have BIOS stored on a flashmemory chip. As another example, it is becoming increasingly common forcomputers and other devices to utilize flash memory in solid statedrives to replace conventional hard drives. As yet another example,flash memory is popular in wireless electronic devices because itenables manufacturers to support new communication protocols as theybecome standardized, and to provide the ability to remotely upgrade thedevices for enhanced features.

NAND may be a basic architecture of flash memory, and may be configuredto comprise vertically-stacked memory cells.

Before describing NAND specifically, it may be helpful to more generallydescribe the relationship of a memory array within an integratedarrangement. FIG. 1 shows a block diagram of a prior art device 1000which includes a memory array 1002 having a plurality of memory cells1003 arranged in rows and columns along with access lines 1004 (e.g.,wordlines to conduct signals WL0 through WLm) and first data lines 1006(e.g., bitlines to conduct signals BL0 through BLn). Access lines 1004and first data lines 1006 may be used to transfer information to andfrom the memory cells 1003. A row decoder 1007 and a column decoder 1008decode address signals A0 through AX on address lines 1009 to determinewhich ones of the memory cells 1003 are to be accessed. A senseamplifier circuit 1015 operates to determine the values of informationread from the memory cells 1003. An I/O circuit 1017 transfers values ofinformation between the memory array 1002 and input/output (I/O) lines1005. Signals DQ0 through DQN on the I/O lines 1005 can represent valuesof information read from or to be written into the memory cells 1003.Other devices can communicate with the device 1000 through the I/O lines1005, the address lines 1009, or the control lines 1020. A memorycontrol unit 1018 is used to control memory operations which are to beperformed on the memory cells 1003, and utilizes signals on the controllines 1020. The device 1000 can receive supply voltage signals Vcc andVss on a first supply line 1030 and a second supply line 1032,respectively. The device 1000 includes a select circuit 1040 and aninput/output (I/O) circuit 1017. The select circuit 1040 can respond,via the I/O circuit 1017, to signals CSEL1 through CSELn to selectsignals on the first data lines 1006 and the second data lines 1013 thatcan represent the values of information to be read from or to beprogrammed into the memory cells 1003. The column decoder 1008 canselectively activate the CSEL1 through CSELn signals based on the A0through AX address signals on the address lines 1009. The select circuit1040 can select the signals on the first data lines 1006 and the seconddata lines 1013 to provide communication between the memory array 1002and the I/O circuit 1017 during read and programming operations.

The memory array 1002 of FIG. 1 may be a NAND memory array, and FIG. 2shows a block diagram of a three-dimensional NAND memory device 200which may be utilized for the memory array 1002 of FIG. 1. The device200 comprises a plurality of strings of charge-storage devices. In afirst direction (Z-Z′), each string of charge-storage devices maycomprise, for example, thirty-two charge-storage devices stacked overone another with each charge-storage device corresponding to one of, forexample, thirty-two tiers (e.g., Tier0-Tier31). The charge-storagedevices of a respective string may share a common channel region, suchas one formed in a respective pillar of semiconductor material (e.g.,polysilicon) about which the string of charge-storage devices is formed.In a second direction (X-X′), each first group of, for example, sixteenfirst groups of the plurality of strings may comprise, for example,eight strings sharing a plurality (e.g., thirty-two) of access lines(i.e., “global control gate (CG) lines”, also known as wordlines, WLs).Each of the access lines may couple the charge-storage devices within atier. The charge-storage devices coupled by the same access line (andthus corresponding to the same tier) may be logically grouped into, forexample, two pages, such as P0/P32, P1/P33, P2/P34 and so on, when eachcharge-storage device comprises a cell capable of storing two bits ofinformation. In a third direction (Y-Y′), each second group of, forexample, eight second groups of the plurality of strings, may comprisesixteen strings coupled by a corresponding one of eight data lines. Thesize of a memory block may comprise 1,024 pages and total about 16 MB(e.g., 16 WLs×32 tiers×2 bits=1,024 pages/block, block size=1,024pages×16 KB/page=16 MB). The number of the strings, tiers, access lines,data lines, first groups, second groups and/or pages may be greater orsmaller than those shown in FIG. 2.

FIG. 3 shows a cross-sectional view of a memory block 300 of the 3D NANDmemory device 200 of FIG. 2 in an X-X′ direction, including fifteenstrings of charge-storage devices in one of the sixteen first groups ofstrings described with respect to FIG. 2. The plurality of strings ofthe memory block 300 may be grouped into a plurality of subsets 310,320, 330 (e.g., tile columns), such as tile column_(I), tile column_(j)and tile column_(K), with each subset (e.g., tile column) comprising a“partial block” of the memory block 300. A global drain-side select gate(SGD) tine 340 may be coupled to the SGDs of the plurality of strings.For example, the global SGD line 340 may be coupled to a plurality(e.g., three) of sub-SGD lines 342, 344, 346 with each sub-SGD linecorresponding to a respective subset (e.g., tile column), via acorresponding one of a plurality (e.g., three) of sub-SGD drivers 332,334, 336. Each of the sub-SGD drivers 332, 334, 336 may concurrentlycouple or cut off the SGDs of the strings of a corresponding partialblock (e.g., tile column) independently of those of other partialblocks. A global source-side select gate (SGS) line 360 may be coupledto the SGSs of the plurality of strings. For example, the global SGSline 360 may be coupled to a plurality of sub-SGS lines 362, 364, 366with each sub-SGS line corresponding to the respective subset (e.g.,tile column), via a corresponding one of a plurality of sub-SGS drivers322, 324, 326. Each of the sub-SGS drivers 322, 324, 326 mayconcurrently couple or cut off the SGSs of the strings of acorresponding partial block (e.g., tile column) independently of thoseof other partial blocks. A global access line (e.g., a global CG line)350 may couple the charge-storage devices corresponding to therespective tier of each of the plurality of strings. Each global CG line(e.g., the global CG line 350) may be coupled to a plurality ofsub-access lines (e.g., sub-CG lines) 352, 354, 356 via a correspondingone of a plurality of sub-string drivers 312, 314 and 316. Each of thesub-string drivers may concurrently couple or cut off the charge-storagedevices corresponding to the respective partial block and/or tierindependently of those of other partial blocks and/or other tiers. Thecharge-storage devices corresponding to the respective subset (e.g.,partial block) and the respective tier may comprise a “partial tier”(e.g., a single “tile”) of charge-storage devices. The stringscorresponding to the respective subset (e.g., partial block) may becoupled to a corresponding one of sub-sources 372, 374 and 376 (e.g.,“tile source”) with each sub-source being coupled to a respective powersource.

The NAND memory device 200 is alternatively described with reference toa schematic illustration of FIG. 4.

The memory array 200 includes wordlines 202 ₁ to 202 _(N), and bitlines228 ₁ to 228 _(M).

The memory array 200 also includes NAND strings 206 ₁ to 206 _(M). EachNAND string includes charge-storage transistors 208 ₁ to 208 _(N). Thecharge-storage transistors may use floating gate material (e.g.,polysilicon) to store charge, or may use charge-trapping material (suchas, for example, silicon nitride, metallic nanodots, etc.) to storecharge.

The charge-storage transistors 208 are located at intersections ofwordlines 202 and strings 206. The charge-storage transistors 208represent non-volatile memory cells for storage of data. Thecharge-storage transistors 208 of each NAND string 206 are connected inseries source-to-drain between a source-select device (e.g., source-sideselect gate, SGS) 210 and a drain-select device (e.g., drain-side selectgate, SGD) 212. Each source-select device 210 is located at anintersection of a string 206 and a source-select line 214, while eachdrain-select device 212 is located at an intersection of a string 206and a drain-select line 215. The select devices 210 and 212 may be anysuitable access devices, and are generically illustrated with boxes inFIG. 1.

A source of each source-select device 210 is connected to a commonsource line 216. The drain of each source-select device 210 is connectedto the source of the first charge-storage transistor 208 of thecorresponding NAND string 206. For example, the drain of source-selectdevice 210 ₁ is connected to the source of charge-storage transistor 208₁ of the corresponding NAND string 206 ₁. The source-select devices 210are connected to source-select line 214.

The drain of each drain-select device 212 is connected to a bitline(i.e., digit line) 228 at a drain contact. For example, the drain ofdrain-select device 212 ₁ is connected to the bitline 228 ₁. The sourceof each drain-select device 212 is connected to the drain of the lastcharge-storage transistor 208 of the corresponding NAND string 206. Forexample, the source of drain-select device 212 ₁ is connected to thedrain of charge-storage transistor 208 _(N) of the corresponding NANDstring 206 ₁.

The charge-storage transistors 208 include a source 230, a drain 232, acharge-storage region 234, and a control gate 236. The charge-storagetransistors 208 have their control gates 236 coupled to a wordline 202.A column of the charge-storage transistors 208 are those transistorswithin a NAND string 206 coupled to a given bitline 228. A row of thecharge-storage transistors 208 are those transistors commonly coupled toa given wordline 202.

It would be desirable to develop improved memory array architecture(e.g., improved NAND architecture), and to develop methods forfabricating the improved memory array architecture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a block diagram of a prior art memory device having amemory array with memory cells.

FIG. 2 shows a schematic diagram of the prior art memory array of FIG. 1in the form of a 3D NAND memory device.

FIG. 3 shows a cross-sectional view of the prior art 3D NAND memorydevice of FIG. 2 in an X-X′ direction.

FIG. 4 is a schematic of a prior art NAND memory array.

FIG. 5 is a diagrammatic top view of a region of a prior art integratedassembly illustrating an example architecture.

FIGS. 5A and 5B are diagrammatic cross-sectional side views along thelines A-A and B-B, respectively, of the prior art FIG. 5.

FIG. 6 is a diagrammatic top view of a region of a prior art integratedassembly illustrating another example architecture.

FIGS. 6A and 613 are diagrammatic cross-sectional side views along thelines A-A and B-B, respectively, of the prior art FIG. 6.

FIGS. 7-10 are diagrammatic top views of a region of a prior artintegrated assembly at example process stages of an example method forfabricating an example structure.

FIGS. 7A-10A and 7B-10B are diagrammatic cross-sectional side viewsalong the lines A-A and B-B, respectively, of prior art FIGS. 7-10, FIG.8C is a diagrammatic cross-sectional side view along the line C-C ofprior art FIG. 8.

FIGS. 11-14 are diagrammatic top views of a region of an integratedassembly at example process stages of an example method for fabricatingan example structure.

FIGS. 11A-14A and 11B-14B are diagrammatic cross-sectional side viewsalong the lines A-A and B-B, respectively, of FIGS. 11-14. FIG. 12C is adiagrammatic cross-sectional side view along the line C-C of FIG. 12.

FIG. 15 is a diagrammatic top view of a region of an integrated assemblyillustrating another example architecture.

FIGS. 15A and 15B are diagrammatic cross-sectional side views along thelines A-A and B-B, respectively, of FIG. 15.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Some embodiments include recognition that a problem which may beencountered during fabrication of vertically-stacked memory (e.g.,three-dimensional NAND) is unintended etching of supportingsemiconductor material. Such may lead to problematic collapse ofvertically-stacked structures, and may ultimately lead to devicefailure. Some embodiments include recognition that the problem mayresult from exposure of metal-containing conductive material under aregion of the semiconductor material, followed by galvanic removal ofthe semiconductor material during subsequent processing. Someembodiments also include recognition that the problem may be alleviatedby providing thickened regions of the semiconductor material atlocations where etching would otherwise expose the underlyingmetal-containing conductive material. Example embodiments are describedwith reference to FIGS. 5-15.

Referring to FIGS. 5-5B, regions of an example integrated assembly 10are illustrated. The assembly includes a block region (labeled “Block”)which is subdivided amongst a pair of the sub-blocks (labeled“Sub-block₁” and “Sub-block₂”). The block region is within a tile region(labeled “Tile”). The sub-blocks, block and tile may be arranged inconfigurations suitable for three-dimensional NAND architecture, suchas, for example, architectures of the types described above in FIGS.1-4.

A partition 12 extends around the sub-blocks, and separates thesub-blocks from one another. The partition 12 comprises a partitionmaterial 14. The partition material 14 may comprise any suitablecomposition(s); and in some embodiments may comprise, consistessentially of, or consist of silicon dioxide.

The block is laterally offset from a staircase region (labeled“Staircase Region”), which is a region where electrical contact is madeto stacked conductive levels within the sub-blocks.

The cross-sectional views of FIGS. 5A and 5B show that the assembly 10includes a stack 16 of alternating conductive levels 18 and insulativelevels 20. The levels 18 comprise conductive material 19, and the levels20 comprise insulative material 21.

The conductive material 19 may comprise any suitable electricallyconductive composition(s), such as, for example, one or more of variousmetals (e.g., titanium, tungsten, cobalt, nickel, platinum, ruthenium,etc.), metal-containing compositions (e.g., metal silicide, metalnitride, metal carbide, etc.), and/or conductively-doped semiconductormaterials (e.g., conductively-doped silicon, conductively-dopedgermanium, etc.). In some embodiments, the conductive material 19 mayinclude metal (e.g., tungsten) and metal nitride (e.g., tantalumnitride, titanium nitride, etc.).

The insulative material 21 may comprise any suitable composition(s); andin some embodiments may comprise, consist essentially of, or consist ofsilicon dioxide.

The levels 18 and 20 may be of any suitable thicknesses; and may be thesame thickness as one another, or different thicknesses relative to oneanother. In some embodiments, the levels 18 and 20 may have verticalthicknesses within a range of from about 10 nanometers (nm) to about 400nm.

In some embodiments, the lower conductive level may be representative ofa source-select device (e.g., source-side select gate, SGS); and theupper conductive levels may be representative of wordline levels. Thesource-select-device level may or may not comprise the same conductivematerial(s) as the wordline levels.

Although only three conductive levels 18 are shown in FIGS. 5A and 5B inorder to simplify the drawings, in practice there may be substantiallymore than three conductive levels in the stack 16. For instance, thewordline levels may ultimately correspond to memory cell levels of aNAND configuration. The NAND configuration will include strings ofmemory cells (i.e., NAND strings), with the number of memory cells inthe strings being determined by the number of vertically-stackedwordline levels. The NAND strings may comprise any suitable number ofmemory cell levels. For instance, the NAND strings may have 8 memorycell levels, 16 and memory cell levels, 32 memory cell levels, 64 memorycell levels, 512 memory cell levels, 1024 memory cell levels, etc. Also,the source-select device may include more than one conductive level.

The stack 16 and partition 12 are supported over a conductive structure22. Such conductive structure comprises semiconductor material 24 overthe metal-containing material 26. In the illustrated embodiment, thesemiconductor material 24 is directly against the metal-containingmaterial 26.

The semiconductor material 24 may comprise any suitable composition(s);and in some embodiments may comprise, consist essentially of, or consistof one or more of silicon, germanium, III/V semiconductor material(e.g., gallium phosphide), semiconductor oxide, etc.; with the termIII/V semiconductor material referring to semiconductor materialscomprising elements selected from groups III and V of the periodic table(with groups III and V being old nomenclature, and now being referred toas groups 13 and 15). In some embodiments, the semiconductor material 24may comprise conductively-doped silicon; such as, for example, n-typedoped polysilicon.

The metal-containing material 26 may comprise any suitablecomposition(s), such as, for example, one or more of various metals(e.g., titanium, tungsten, cobalt, nickel, platinum, ruthenium, etc.)and/or metal-containing compositions (e.g., metal silicide, metalnitride, metal carbide, etc.).

In some embodiments, the conductive structure 22 may correspond to asource structure (e.g., a structure comprising the so-called commonsource line 216 of FIG. 4). The source structures of FIGS. 1-4 arereferred to as “lines” in accordance with traditional nomenclature, butsuch lines may be comprised by an expanse rather than a simple wiringline; such as the expanse shown in FIGS. 5A and 5B as structure 22.

Vertically-stacked memory cells (not shown in FIGS. 5-5B) may beprovided within the stack 16 along the conductive wordline levels. Suchmemory cells may be arranged in vertical NAND strings of the typesdescribed in FIGS. 1-4. The NAND strings may comprise channel materialpillars which extend through the stack 16, with the channel materialbeing electrically coupled with the semiconductor material 24 of theconductive structure 22. The channel material pillars may be arrangedwithin the sub-blocks in any suitable configuration; and in someembodiments may be in a tightly-packed arrangement, such as, forexample, a hexagonally-packed arrangement.

The conductive structure 22 may be supported by a semiconductorsubstrate (not shown). The term “semiconductor substrate” means anyconstruction comprising semiconductive material, including, but notlimited to, bulk semiconductive materials such as a semiconductive wafer(either alone or in assemblies comprising other materials), andsemiconductive material layers (either alone or in assemblies comprisingother materials). The term “substrate” refers to any supportingstructure, including, but not limited to, the semiconductor substratesdescribed above.

The conductive structure 22 is shown to be electrically coupled withCMOS (complementary metal oxide semiconductor). The CMOS may be in anysuitable location relative to the conductive structure 22, and in someembodiments may be under such conductive structure. The CMOS maycomprise logic or other appropriate circuitry for driving the sourcestructure 22 during operation of memory associated with the stack 16.Although the circuitry is specifically identified to be CMOS in theembodiment of FIGS. 5A and 5B, it is to be understood that suchcircuitry could be replaced with any other suitable circuitry in otherembodiments.

FIGS. 5-5B show a desired arrangement in which the stack 16 is supportedover the conductive structure 22. However, in practice is sometimesfound that the actual arrangement has a warped, or broken stack as shownin FIGS. 6-6B. Specifically, FIGS. 6-6B show the assembly 10 afterprocessing has undesirably removed a substantial amount of thesemiconductor material 24 of conductive structure 22, leading toformation of voids 28 between the stack 16 and the conductive material26. The voids 28 may cause partial and/or total collapse of some of theregions of the stack 16; which may detrimentally alter deviceperformance, and which may even lead to device failure. Sunken regionsof the stack 16 are diagrammatically indicated as being withindashed-line regions in the top view of FIG. 6.

One aspect of the invention described herein is recognition that thevoids 28 may result from galvanic corrosion of the semiconductormaterial 24, as discussed with reference to FIGS. 7-10.

Referring to FIGS. 7-7B, a region of assembly 10 is shown at a processstage during fabrication of the conductive wordlines of stack 16 (withthe conductive wordlines ultimately being within the conductive levels18 described above with reference to FIG. 5). The staircase region isnot shown in order to simplify the discussion of the processing. It wasnoted above in describing FIG. 5 that the upper conductive levels 18 maycorrespond to wordlines and the lower level(s) may correspond to onemore select device levels. The processing described herein forms all ofthe levels 18 identically with a gate-replacement process (described inFIGS. 7-10). In other embodiments, the select device levels may not besubjected to the gate replacement processing.

The assembly 10 of FIGS. 7-7B includes a stack 29 of alternating firstand second levels 30 and 20. The second levels 20 are identical to theinsulative levels 20 described above with reference to FIGS. 5-5B, andcomprise the insulative material 21. The first levels 30 comprisesacrificial material 31. Such sacrificial material may comprise anysuitable composition(s); and in some embodiments may comprise, consistessentially of, or consist of silicon nitride.

The stack 29 is supported over the conductive structure 22. In theillustrated embodiment, the conductive structure 22 is coupled with CMOSat the processing stage of FIGS. 7-7B. In other embodiments, thecoupling to the CMOS may be provided at a subsequent process stage.

Referring to FIGS. 8-8C, slits 32 are formed through the stack 29 to theconductive structure 22. The slits 32 join to one another at intersectregions 34. The intersect regions are wider than other portions of theslits, and accordingly the etching utilized to form the slits may formcavities 36 in the semiconductor material 24 at the intersect regions 34during the duration of the etch utilized to expose semiconductormaterial 24 at the non-intersect regions of the slits 32. At least oneof the cavities 36 may extend through the semiconductor material 24 toexpose the metal-containing material 26 of the conductive structure 22.

Referring to FIGS. 9-9B, the sacrificial material 31 (FIGS. 8-8C) isreplaced with conductive material 19 to form the stack 16 describedabove with reference to FIGS. 5-5B. Such replacement may utilize an etchto remove the sacrificial 31 (for instance, an etch selective forsilicon nitride relative to silicon dioxide in applications in which thesacrificial material 31 comprises silicon nitride and the insulativematerial 21 comprises silicon dioxide), followed by deposition of theconductive material 19, and then followed by suitable etching to removeexcess conductive material 19 from within the slits 32.

The semiconductor material 24 (e.g., conductively-doped silicon) wouldgenerally be resistant to the various etches utilized during thereplacement of the sacrificial material 31 with the conductive material19. However, the exposure of conductive material 26 within the cavities36 (as shown in FIGS. 8A and 8C) enables a galvanic reaction to occurduring one or more of the etches which undesirably removes some of theconductive material 24, and thereby forms the voids 28. The galvanicreaction is described as a possible mechanism for the removal of thesemiconductor material 24 to assist the reader in understanding theinvention described herein. The actual mechanism underlying the removalof the semiconductor material 24 may involve other reactions in additionto, or alternatively to, the galvanic reaction described herein. Theclaims that follow are not to be limited to any specific reactionmechanism described herein except to the extent, if any, that suchreaction mechanism is specifically recited in the claims.

Referring to FIGS. 10-10B, insulative material 14 is formed within theslits 32 to thereby form the partition 12 described above with referenceto FIGS. 5-5B. Unfortunately, the voids 28 weaken the support underregions of stack 16, which can lead to the warping, collapse, etc.,described above with reference to FIGS. 6-6B.

Some embodiments include configurations which may prevent the problemsdescribed with reference to FIGS. 6-10. FIGS. 11-14 describe an exampleconfiguration, and describe an example method in which suchconfiguration may prevent the problems described above with reference toFIGS. 6-10.

Referring to FIGS. 11-11B, construction 10 is shown at a processingstage analogous to that described above with reference to FIGS. 7-7B.The construction of FIGS. 11-11B includes the stack 29 having thealternating first and second levels 20 and 30.

The embodiment of FIGS. 11-11B differs from that of FIGS. 7-7B in thatthe conductive structure 22 comprises first and second portions 38 and40, as shown in FIG. 11A. The first portion 38 comprises a thickerregion of the semiconductor material 24 than does the second portion 26.The thicker first portion 38 of the semiconductor material 24 will be inlocations where the cavities 36 problematically occur in the processingdescribed above with reference to FIGS. 8-8C. In the shown embodiment,the first portion 38 only comprises the semiconductor material 24. Inother embodiments, the first portion may also comprise themetal-containing material 26, provided that the semiconductor material24 is thick enough in the first portion 38 so that cavities formed insuch first portion do not reach the metal-containing material.

In some embodiments, the conductive structure 22 may be considered tohave an overall thickness T. Such overall thickness may be any suitablethickness; and in some embodiments may be within a range of from about500 (angstroms) Å to about 5000 Å. The semiconductor material 24 may beconsidered to have a first thickness T₁ within the first portion 38 ofthe conductive structure 22, and to have a second thickness T₂ withinthe second portion 40 of the conductive structure 22. In someembodiments, the first thickness T₁ may be greater than or equal toabout half of the overall thickness T (i.e., the second thickness T₂ maybe less than or equal to about half of the overall thickness T). In theshown embodiment in which there is no metal-containing material 26within the first portion 38, the first thickness T₁ of the semiconductormaterial 24 within the first portion 38 is equal to the overallthickness T.

Referring to FIGS. 12-12C, the slits 32 are formed through the stack 30to the conductive structure 22. The slits join to one another at theintersect regions 34 described above with reference to FIGS. 8-8C, andcavities 36 may form in locations of the conductive structure 22 undersuch intersect regions for the reasons discussed above with reference toFIGS. 8-8C. The construction of FIGS. 12-12C has the first portion 38 ofthe conductive structure 22 under the intersect regions 34; andaccordingly the cavities 36 extend only into the semiconductor material24 and do not expose the underlying metal-containing material 26.Notably, only the first portion 38 of the conductive structure 22 isunder the intersect regions 34, and the second portion 40 of theconductive structure 22 (i.e., the portion of the conductive structurehaving the relatively thin semiconductor material 24 over themetal-containing material 26) is not under the intersect regions 34.

The cavities 36 may have uniform dimensions relative to one another, ormay be of substantially different dimensions relative to one another. Insome embodiments, at least one of the cavities 36 will have a depth Dwhich is deeper than the thickness T₂ of the semiconductor material 24across the second portion 40 of the conductive material 22 (e.g., mayhave a depth within a range of from at least about 250 Å to about 2500Å). In some embodiments, one or more of the cavities 36 may have across-sectional width (e.g., a width W along the cross-section of FIG.12A) within a range of from about 100 nanometers (nm) to about 400 nm.

Referring to FIGS. 13-13B, the sacrificial material 30 (FIGS. 12-12C) isreplaced with the conductive material 19 utilizing methodologies of thetype described above with reference to FIGS. 9-9B. However, since themetal-containing material 26 is not exposed in the construction of FIGS.13-13B, the problematic galvanic reaction of FIGS. 9-9B is avoided.

Referring to FIGS. 14-14B, the insulative material 14 is formed withinthe slits 32 to thereby form the partition 12.

In some embodiments, at least some of the conductive levels 18 maycorrespond to wordlines levels, and accordingly at least some of theconductive material 19 may correspond to a wordline material of a NANDassembly. The partition 12 may divide such NAND assembly into sub-blocksof the type described above with reference to FIGS. 5-5B.

The partition 12 of FIGS. 14-14B directly contacts a top surface 25 ofthe conductive structure 24. Such top surface comprises thesemiconductor material 24; and in some embodiments may comprise, consistessentially of or consist of conductively-doped silicon (e.g., n-typedoped polysilicon).

In some embodiments, the partition 12 may be considered to comprise wallregions 50, and to comprise corner regions 52 where two or more wallregions meet. The first portion 38 of the conductive structure 22 isdirectly under the corner regions 52, and the second portion 40 of theconductive structure 22 is directly under the wall regions 50. Thesecond portion 40 of the conductive structure 22 does not extend tounder the corner regions 52. In the shown embodiment, a cavity 36 isalso under a corner region 52 of the partition 12, as illustrated inFIG. 14A.

The entirety of stack 16 of FIGS. 5-5B is shown starting from the stack29 of FIGS. 11-11B. In some applications, only a portion of the stack 16will start from the stack 29. For instance, the lower conductivelevel(s) of the stack may correspond to SGS levels comprising differentconductive material than that of the of the wordline levels (i.e., theupper conductive levels). In such embodiments, the conductive materialof the lower level(s) may be provided at a processing stage prior tothat of FIGS. 11-11B, and only the conductive material of the wordlinelevels will be replaced utilizing the gate replacement methodologiesdescribed with reference to FIGS. 13-13B.

In the embodiment of FIGS. 14-14B, the partition 12 only comprisesinsulative material 14. In other embodiments, the partition 12 may haveother configurations. For instance, FIGS. 15-15B shown an embodimentsimilar to that of FIGS. 14-14B, but in Which the partition 12 comprisesinsulative panels 60 on opposing sides of a conductive core 62.

The insulative panels 60 comprise insulative material 64. Such materialmay comprise any suitable composition(s); and in some embodiments maycomprise, consist essentially of, or consist of silicon dioxide.

The conductive core 62 comprises conductive material 66. Such conductivematerial may comprise any suitable electrically conductivecomposition(s), such as, for example, one or more of various metals(e.g., titanium, tungsten, cobalt, nickel, platinum, ruthenium, etc.),metal-containing compositions (e.g., metal silicide, metal nitride,metal carbide, etc.), and/or conductively-doped semiconductor materials(conductively-doped silicon, conductively-doped germanium, etc.).

In the illustrated embodiment, the conductive material 66 directlycontacts the upper conductive surface 25 of the conductive structure 22.In other embodiments, the conductive core may or may not directlycontact such upper conductive surface 25.

The assemblies and structures discussed above may be utilized withinintegrated circuits (with the term “integrated circuit” meaning anelectronic circuit supported by a semiconductor substrate); and may beincorporated into electronic systems. Such electronic systems may beused in, for example, memory modules, device drivers, power modules,communication modems, processor modules, and application-specificmodules, and may include multilayer, multichip modules. The electronicsystems may be any of a broad range of systems, such as, for example,cameras, wireless devices, displays, chip sets, set top boxes, games,lighting, vehicles, clocks, televisions, cell phones, personalcomputers, automobiles, industrial control systems, aircraft, etc.

Unless specified otherwise, the various materials, substances,compositions, etc. described herein may be formed with any suitablemethodologies, either now known or yet to be developed, including, forexample, atomic layer deposition (ALD), chemical vapor deposition (CVD),physical vapor deposition (PVD), etc.

The terms “dielectric” and “insulative” may be utilized to describematerials having insulative electrical properties. The terms areconsidered synonymous in this disclosure. The utilization of the term“dielectric” in some instances, and the term “insulative” (or“electrically insulative”) in other instances, may be to providelanguage variation within this disclosure to simplify antecedent basiswithin the claims that follow, and is not utilized to indicate anysignificant chemical or electrical differences.

The particular orientation of the various embodiments in the drawings isfor illustrative purposes only, and the embodiments may be rotatedrelative to the shown orientations in some applications. Thedescriptions provided herein, and the claims that follow, pertain to anystructures that have the described relationships between variousfeatures, regardless of whether the structures are in the particularorientation of the drawings, or are rotated relative to suchorientation.

The cross-sectional views of the accompanying illustrations only showfeatures within the planes of the cross-sections, and do not showmaterials behind the planes of the cross-sections, unless indicatedotherwise, in order to simplify the drawings.

When a structure is referred to above as being “on”, “adjacent” or“against” another structure, it can be directly on the other structureor intervening structures may also be present. In contrast, when astructure is referred to as being “directly on”, “directly adjacent” or“directly against” another structure, there are no interveningstructures present.

Structures (e.g., layers, materials, etc.) may be referred to as“extending vertically” to indicate that the structures generally extendupwardly from an underlying base (e.g., substrate). Thevertically-extending structures may extend substantially orthogonallyrelative to an upper surface of the base, or not.

Some embodiments include an integrated assembly having a conductivestructure which includes a semiconductor material over ametal-containing material. A stack of alternating conductive levels andinsulative levels is over the conductive structure. A partition extendsthrough the stack and directly contacts a top of the conductivestructure. The partition has wall regions, and has corner regions wheretwo or more wall regions meet. The conductive structure includes a firstportion which extends directly under the corner regions, and includes asecond portion which is directly under the wall regions and is notdirectly under the corner regions. The first portion has a firstthickness of the semiconductor material and the second portion has asecond thickness of the semiconductor material. The first thickness isgreater than the second thickness.

Some embodiments include an integrated assembly having a conductivestructure which comprises a semiconductor material over ametal-containing material. A NAND assembly is over the conductivestructure and comprises a stack of wordline levels. A partition extendsthrough the stack. The partition comprises wall regions, and comprisescorner regions where two or more wall regions meet. The partitiondivides the NAND assembly into sub-blocks. The conductive structurecomprises a first portion which extends to directly under the cornerregions, and comprises a second portion which is directly under the wallregions and is not directly under the corner regions. The first portioncomprises a thicker region of the semiconductor material than the secondportion.

Some embodiments include a method of forming an integrated assembly. Aconstruction is formed to comprise a conductive structure, and tocomprise a stack of alternating first and second levels over theconductive structure. The conductive structure comprises a semiconductormaterial over a metal-containing material. The conductive structurecomprises a first portion and a second portion. The first portioncomprises a thicker region of the semiconductor material than the secondportion. The first levels comprise a first composition and the secondlevels comprise a second composition. The second composition isdifferent than the first composition. Slits are formed to extend throughthe stack to the conductive structure. The slits join to one another atintersect regions. The intersect regions are over the first portion ofthe conductive structure and are not over the second portion of theconductive structure. After the slits are formed, the first compositionis replaced with conductive material. Insulative material is formedwithin the slits.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

1.-28. (canceled)
 29. A method of forming an integrated assembly,comprising: forming a conductive structure comprising a semiconductormaterial, the conductive structure comprising a first portion and asecond portion, the first portion comprising a thicker region of thesemiconductor material than the second portion; forming a stack ofalternating first and second levels over the conductive structure; andforming slits extending through the stack, the slits joining to oneanother at intersect regions, the intersect regions being over the firstportion of the conductive structure and not over the second portion ofthe conductive structure.
 30. The method of claim 29 wherein the firstlevels comprise a first composition and the second levels comprise asecond composition, the second composition being different than thefirst composition.
 31. The method of claim 30 wherein, after forming theslits, replacing the first composition with conductive material.
 32. Themethod of claim 29 further comprising forming insulative material withinthe slits.
 33. The method of claim 30 wherein the first compositioncomprises silicon nitride, and wherein the second composition comprisessilicon dioxide.
 34. The method of claim 29 wherein the formation of theslits forms cavities extending into the first portion under theintersect regions.
 35. The method of claim 34 wherein at least one ofthe cavities is deeper than the second thickness.
 36. The method ofclaim 29 wherein the conductive structure comprises a metal-containingmaterial.
 37. The method of claim 36 wherein the semiconductor materialis over the metal-containing material.
 38. An integrated assembly,comprising: a semiconductor material; a stack of alternating levels overthe semiconductor material; a partition extending through the stack andcomprising wall regions, and comprising corner regions where two or morewall regions meet; and the semiconductor material comprising a firstportion which extends directly under the corner regions, and comprisinga second portion which is directly under the wall regions; the firstportion comprising a first thickness of the semiconductor material andthe second portion comprising a second thickness of the semiconductormaterial; the first thickness being greater than the second thickness.39. The integrated assembly of claim 38 wherein the second portion isnot directly under the corner regions.
 40. The integrated assembly ofclaim 38 wherein the partition directly contacts a top of thesemiconductor material.
 41. The integrated assembly of claim 38 whereinthe stack comprises alternating conductive levels and insulative levels.42. The integrated assembly of claim 38 wherein the semiconductormaterial comprises conductively doped silicon.
 43. The integratedassembly of claim 38 wherein the partition only comprises insulativematerial.
 44. The integrated assembly of claim 38 further comprisingcavities extending into the first portions, at least one of the cavitiesbeing deeper than the second thickness.
 45. The integrated assembly ofclaim 38 further comprising metal-containing material under thesemiconductor material.
 46. The integrated assembly of claim 38 whereinthe stack comprises wordline levels.
 47. The integrated assembly ofclaim 38 wherein the partition comprises insulative panels on opposingsides of a conductive core.